Steam-boiler.



yum-741,529; PATENTEDOGT.13','1903.

.' J. ,M. MOGLELLON.

STEAM BOILER;

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. 1' ,0 WITNESSES: 'IIVVENTOH ATTORNEYS.

I No. 741,529.

PATENTED OCT. 13

J. M. MOCLBLLON.

. STEAM BOILER. v APPLIOJATION FILED my a, 1902.

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J." MQGLELLON. STEAM BOILER. APPLICATION FILED MAY 6, 1902.

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II: I! I UNITED STATES Patented October 13, 1903 PATENT OFFICE.

JAMES M. MOOLELLON, or EVERETT, MASSACHUSETTS.

STEAM-BOILER.

SPEGIFIGA'LTON formingpart of Letters Patent No. 741,529, dated October13, 1903.

Application filed May 6,1962. Serial No. 106,169. (No modem.

T0 at whom it may concern:

Be it known that I, JAMES M. MOCLELLON,

a citizen of the United States'residing at Everett, in the county ofSufiolk and State of Massachusetts, haveinvented a new and ImprovedSteam-Boiler, of which the following is a full, clear, and exactdescription.

My invention relates toimprovements in steam-boilers, the same beingmore-particularly directed to structures of that type adapted for useinlocomotive-engines, although it is to be understood that parts of theinvention may be utilized in the constructionof other types of boilers.

.One object of the invention is the production of an improved boilerhaving a heatingsurface of large area and which secures the circulationof water in a natural manner by reason of thefact that partially-heatedwater is free to enter at the lower part of circulating-tubes, while thesteam and hot water is discharged freely at the upper part of saidtubes. 7 v

A further object of the invention is to provide for the easy removal ofa leaky 'or burned-out tube and its. replacement by a fresh tube withease and facility, all of the tubes being accessible from the outside ofthe boiler.

A- further object of the invention is the production of a novel formof'boiler which has great strength and in which the watertubes are allof the same length and are therefore interchangeable.

A still further object of the invention is the production of a novelform of boiler which while having a large heating-surface issoconstructed that it can be set comparatively low upon the engine withoutinterfering with the operation of the drivers.

With these ends in view the invention consists in the novel combination,construction, and arrangement of. parts,which will be hereinafter fullydescribed, and the actual scope of the invention will be defined by theclaims.

Reference is to be had to the accompanying drawings, forminga part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the figures.

Figure l is a longitudinal sectional elevation through a water-tubesteam-boiler of 'tirely surrounds the inner shell.

the locomotive type embodyingmy improvemerits. Fig. 2 is a verticaltransverse sectional elevation taken in the plane indicated by thedotted'line 2 2 of Fig. 1. Fig. 3 is a detail horizontal section throughthe steam-' dome and taken in the plane of the dotted line 3 3 of Fig. 2with parts broken away.

detail sectional view through the upper part of one of the watercirculating tubes in order to more clearly show the constructionthereof. 4

The boiler consists of an inner shell, (indicated in its entirety by theletter A,) an outer shell B, a plurality of rows of inclinedtubes OD,'"which are preferably arranged in cross ing relation, and other rowsof bent tubes E F. The shells'are concentrically arranged and arepolygonal in cross-section and form between them a water-chamber, whichen- 7 In the present embodimentof my invention the shells are shown asbeing substantially square in cross-section and will be arranged so thatthe sides of the square stand at substantially forty-five degrees,although my invention would not be departed from if the shells weregiven some other polygonal shape. I

it ispossible to set the boiler lower upon the engine withoutinterfering with the drivers than would be possible if the boiler werecylindrical in cross-section.

The inner shell A may be formed, in any suitable Way; but, as hereinshown, it consists of two sheets, each of which is bent to form themembers a a, and these sheets at the the box end of theboiler are bentor fashioned so as to produce the depending portions a The members a aof the parts or sheets comprising the inner shell are bent substantiallyat right angles to each other, and the cross-sectional shape (shown inFigs. 2 and 4) employed at this end of the boiler.

upper edges of the members Ct, forming the sheets of the inner shell,are disposed to have overlapping relation, as at a while the lowerportions of the members a of the sheets or parts of the inner shell arearranged to meet each other beyond the fire-box in order to form thejoint at, (indicated in Fig. 2,) where by the parts or sheets of saidinner shell may be united together in any suitable way, so as to producewater and steam tight joints.

It is evident that the joints between the members of the inner shell canbe packed and riveted in any way known to the art; but this detail ofconstruction may be modified within the skill of a mechanic.

The parts a of the members forming the inner shell are disposed parallelto each other along the sides of the grate-chamber G, and these parallelportions bound or form the side walls of said grate-chamber.

I have herein shown the outer shell B as consisting of the two upperplates 19, forming the upper sides of the boiler, and the plates 17',which are arranged at substantially right angles to each other and formthe under side of the boiler. The plates 1) are united together beyondthe fire-box by a union-strip b and union-strips serve to unite theplates b b. When thusformed, the outer shell has a squarecross-sectional shape which surrounds and is concentric with thesubstantially square inner shell.

At one end of the boiler the plates 11' are formed to present thedepending portions N, which are disposed in parallelism with thedepending portions 662 of the inner shell and which form, with saidportions a water-legs J, surrounding the fire-box.

Any suitable or well-known construction may be resorted to in order tosecure water and steam tight joints between the various plates formingthe outer shell.

By thus arranging the inner and outer shells concentrically a waterchamber is formed between the shells which has substantially uniformdepth, the said waterchamber comprising the upper Water-spaces H, thelower water-spaces I, and the waterlegs J at the sides of the tire-boxor gratechamber, the said water-chamber entirely inclosing the innershell, which constitutes the furnace-flue K and leads from thecombustion or grate chamber G to the smoke-box L, situated at the frontend of the boiler, as is usual in structures of the locomotive type.

The space between the inner and outer shells A B at the rear end of theboiler is closed by the employment of a head g, which may be of theusual or any preferred pattern, said head making provision for access tothe grate-chamber G through the usual firingdoor, although any suitabledevices may be The front end of the outer shell B is extended orprolonged beyond the corresponding end of the inner shell Ain order toform the smokebox L, the latter having direct communication with thelongitudinal flue K, and the space between the front end of the innershell and the outer shell is closed by the employment of a head g, thelatter being so constructed that free communication between thesmoke-box L and the flue K is secured. The grate-chamber G is providedwith a bridge-Wall G, which is preferably formed with a curved top edge9 This top edge of the bridge-wall is concave in order to allow the freeescape of the products of combustion, and to prevent the bridge-wallfrom rapidly deteriorating under the influence of the heat I prefer'tomake it of chambered construction, thereby providing a water-leg G whichlies directly in the path of the escaping heat. This water-leg is indirect communication with the water-legs J at the sides of thegrate-chamber, and the circulation of water from one side leg throughthe bridgewall water-leg to the other side leg is thus obtained. Thiscirculation is not only advantageous in heating the water, but itprevents the bridge-wall from burning out when exposed to the heat ofthe furnace. If desired, the fire-tubes g may be provided in thechambered bridge-wall or front water-leg G said tubes being disposedabove the plane of the grate G4 and making provision for the directapplication of a part of the heat to the water contained in the leg GThe steam-dome M extends practically the full length of the boiler, and,as shown by Figs. 2 and 4, this dome consists of a shell which issubstantially circular in cross'section, the continuity of the shellbeing broken or interrupted at the lower side thereof in order toprovide two longitudinal edges separated by an intervening gap or space.The edges of the shell are disposed in overlapping relation to theflanges b of the upper members forming parts of the outer shell B, andthese overlapping edges of the shell B and the steam-dome are unitedtogether by steam-tight joints. The shell of the steamdome is thusattached directly to the angular outer shell of the boiler, and thissteam-dome communicates throughout itslength with the upper chamber H,which is formed by and between the inner and outer shells A B.

I have found it desirable to provide means which reinforce thesteam-dome shell interiorly thereof, so that the pressure of the steamwill not have a tendency to destroy the water-tight joint between theshell of said dome and the outer shell B. In one embodiment of thereinforcing device a stay-plate m is employed, the same being situatednear the lower part of the dome and having its edges arranged to lap thelower edges of the slotted shell. This stay may be united to the Thestay is provided with orifices IIO Lil

m, which allow the free and uninterrupted passage of thesteam from thechambers H into the dome M. (See Figs. 2, 3, and 4:.)

In the flue K, which leads from the gratechamber to the smoke-box L, isarranged a plurality of rows of straight inclined watercirculating tubes0 D, as shown more clearly by Fig. 2, the tubes of one row beingdisposed in crossing relation to the tubes of the adjacent rows and allthese tubes lying directly in the path of the escaping products ofcombustion as they circulate through the flue K on their way from thegrate-chamber G into the smoke-box L. The tubes 0 and Dextend parallelto the sides of the boiler, each tube therefore extending across thediameter of the boiler, and as the shells of the boiler are square incross-sectional area it follows that all of the tubes are of the samelength. This is quite an advantage, as it avoids the necessity ofemploying tubes of various length, as would be the case if the boilerwere cylindrical in cross-section. As herein shown, each tube passes atits ends through the inner shell A, across the waterchamber between theshells, and has its end secured to the outer shell, said tubes beingunited to the shells by water and steam tight joints in any approvedway, preferably by expanding said tubes into the shells, as usual inboilers. By thus extending eachof the tubes through the water-chamberand securing its ends in the outer shell I have provided for properlystaying the outer shell to prevent the opposite sides of the latter frombeing spread by the pressure in the boiler. Where the boilershells arerectangular in cross-section, it is imperative that some special meanshe employed for thus staying the outer shell, and by means of myconstruction I accomplish this by means of the water-tubes. The upperside of the upper end of each tube is provided with acirculating-opening c, and the under side of the lower end of each tubehas a corresponding water-inlet or circulating-opening c. This furnishesa communication between each end of the tube and the water-chamber, andthe special position of the circulating-opening c o is designed tofacilitate the entrance of the water from the lower portions I of thewater-chamber into the tubes'and the exit of the water and steam fromthe upper ends of said tubes into the upper portions H of thewater-chamber. The end of each of the tubes is carried entirely throughthe outer shell B, and said ends are closed in any suitable way, as bymeans of caps (1, each of which is provided with an angular or polygonalthe water is more highlyheated by reason of the impingement of theproducts ofcombustion against the tube, and the heated water and steam.can escape freely and in an upward direction through the outlet-opening0 into one of the upper portions H of the water-chamber. Each tube 0 orD is furthermore coustructedwithan expansible portiond near its upperend, said expansible portion (1 being provided by the formation of aproper number of corrugations in the tube at a point adjacent toitsunion with the member a of the inner shell. This corrugated portionat of each tube is thus disposed within the'long'itudinal fiue K,wherein the tube is .subjected to the action of the products ofcombustion, and the provision of this corrugated part of the tubecompensates for expansion and contraction of the tube due to the actionof the heated gases andthe circulation of the water, thereby minimizingany tendency of the expansion or contraction to loosen the tubes in theshells of the boiler.

In that portion of the boiler beyond the fire-box the inner shell issubstantially filled with the inclined crossing tubes, as above stated,these tubes being arranged in rows,the tubes of one row being designatedby D and the other row by O. The tubes of adjacent rows are inclined inopposite directions and stand substantially at right angles toeachother, while the tubesof alternate rows are parallel toeach other.

At the portion of the inner shell over the fire-box it would beimpossible to extend all of the tubes of any row entirel'y across theICO inner shell without choking the grate-chamfire-box. is very muchless than the distance between the outer corners or angles of theboiler. In other words, the shells of the boiler "flare outwardly at apoint-above the fire-box In order to obtain the greatest possible areaof effective heating-surface and at the same time not to choke thegrate-chamber, I employ in addition to the straight tubes which formpart of the'rows over the fire-box the bent tubes E F.

Each tube ofthe'row of bent tubes is curved at a point intermediateofits length, as indicated ate, and forms two limbs or-members e e Thelower end of the limb c of each bent tube is provided with an inletopening 8 is fastened to the shells at the lower part of the boiler, wasto have its opening communicate with one of the chambers I, and isprovided with a cap similar to the cap 01'. The other limb e is passedthrough and united to the shells of the boiler, is provided with anorifice e and is provided with a cap, thus making provision for theescape of the heated water into one of the upper spaces 11. The tubesforming each row of bent tubes gradually increase in length, as shown byFig. 4, and these tubes are disposed in alternate relations to otherstraight tubes, which extend entirely across the flue K and havecommunication with the spaces H 1. Each row of tubes, therefore, overthe gratechamber is composed partially of straight tubes and partiallyof bent tubes, this construction leaving a free open space for propercombustion of the fuel. Owing to the opposite inclination of adjacentrows of tubes, the bent tubes E of one row are adjacent the straighttubes 0 of the next adjacent row, while the straight tubes D of any roware opposite or adjacent the bent tubes F of the next adjacent row.

In the practical construction of the boiler it is my purpose to have thewater-tubes of each series 0 or D disposed in staggered or alternaterelation--that is, one row of tubes 0 are in alternate relation to thetubes of one or more rows of adjacent tubes 0, such arrangement alsoapplying to the tubes D and, if desired, to the tubes E and F. Suchstaggering of the tubes prevents the heat and gases from escapingdirectly through straight passages; but, on the contrary, the escapinggases are deflected by impinging the tubes, so that they will be causedto pursue a tortuous course. By extending each tube clear across thewater-chamber and expanding the same into the outer shell the tubes havethe function of stay members and serve to hold the shells in shape andprevent them from spreading.

With this construction, therefore, it is unnecessary to employ anystay-bolts whatever except at points where tubes do not extend as,forinstance, around the water-legs. Moreover, by thus extending the tubesthrough the outer shell each tube is made readily accessible from theoutside of the boiler, and by merely removing the cap on the end of anyone tube said tube can be cleaned or can be removed without in any waydisturbing any of the other tubes. This I consider to be quite animportant feature of my invention, as with the present type oflocomotiveboilers it is necessary to practically dismantle the boiler inorder to get access to a damaged tube. With my improved boiler, however,any damaged tube may be removed in a very short space of time and a newtube put in its place without in any way disturbing any of the othertubes. Another very important advantage secured by my improved form oflocomotive-boiler is the fact that a boiler having a largeheating-surface can be set comparatively low upon the engine-framewithout interfering with the drivers, for it will be observed that byshaping the boiler so that the diagonals thereon extend vertically andhorizontally the lower apex of the boiler may be received between thedriving-wheels, and thus permit the boiler to be set lower on the framethan would be possible with the same size cylindrical boiler.

lVhile I have herein disclosed the best form of my invention now knownto me, I do not wish to be limited to this construction, as variouschanges may be made in the construction of parts without departing fromthe spirit of my invention.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A locomotive-boilerhaving an inner shell polygonal in cross-sectionand constituting a flue, one end of said shell being shaped to form afire-box, an outer shell concentric with the inner shell and formingwith the latter a wa-- ter-chamber between said shells, inclinedwator-tubes extending across the inner shell and communicating with thewater-chamber, and means to prevent the sides of the outer shell fromspreading.

2. Alocomotive-boiler having an innershell rectangular in cross-section,one end of said shell being shaped to form a fire-box, an outer shellalso rectangular in cross-section and arranged with its sides inparallelism with those of the inner shell, the space between the shellsforming a water-chamber, inclined watertubes extending across the innershell and connecting the opposite sides of the waterchan1ber, and meansto hold the opposite sides of the outer shell from spreading.

3. A locomotive-boiler having concentric inner and outer shells formingbetween them a Water-chamber the inner shell being shaped at one end toform a fire-box, said shells both being substantially rectangular incross-section and arranged with their diagonals in substantiallyvertical and horizontal planes, inclined tubes extending across theinner shell parallel with the sides of the said shell, and means to holdthe opposite sides of the outer shell from spreading.

4:. A locomotive-boiler having inner and outer shells which arerectangular in crosssection and which form between them a water-chamber,said inner shell being shaped at one end to form a fire-box, andinclined water-tubes extending through the inner shell, each of saidtubes having its end portions extending through the water-chamber andsecured to the outer shell.

5. A steam-boiler having concentric inner and outer shells which arerectangular in cross-section, and which form between them awater-chamber, and inclined crossing tubes extending transverselythrough the inner shell, each of said tubes having its end portionsextended through the water-chamber and secured to the outer shell, andan inletopening in the lower side of the lower end of each tube and anoutlet in the upper side of the upper end of each tube.

IIO

. in series to overhang the fire-box, said bent tubes alternating withthe straight tubes which are situated over the fire box.

7. A steam-boiler having a fire-box, a flue extending forwardlytherefrom a water-chamber surrounding the flue and fire-box, rows ofbent tubes overhanging the fire-box and having their end portions incommunication with said water-chamber, and crossing rows of straighttubes disposed across the fire-box and flue, the end portions of saidtubes being in communication with the water-chamber.

8. A steam-boiler having inner and outer shells forming between themwater-spaces, a steam-dome extending longitudinally of the boiler, andhaving direct communication with said water-spaces throughout its entireextent, and inclined tubes disposed between said casing, andcommunicating with the water-spaces at points below the steam-dome.

9. A horizontal boiler having water-spaces at the sides thereof, asteam-dome extending longitudinally of the boiler and having directcommunication with the water-spacesthroughout its entire extent, and aperforated stay spanning the throat of the dome.

10. A steam-boiler having shells polygonal in cross-section, anddisposed in parallel relation, and forming between them a waterchamberwhich surrounds a'longitudinal flue and the sides of a fire-box, ahollow bridgewall forming a water-leg in communication with thewater-chamber, a steam-dome united to the outershell and communicatingdirectly with the water-chamber and water-circulating tubes extendingthrough the outer shell, certain of said tubes overhanging the fire-box.

11. A steam-boiler having concentric inner. and outer shellssubstantially square in crosssection, and forming between them awaterchamber, said shells atone end having depending portions formingafire-box of a widthless than the diameter of the boiler, and meansconnecting opposite sides of said shell and operating to prevent themfrom spreadmg;

12. In a boiler, two concentric shells forming between them awater-chamber,said shells being substantially rectangular incross-section and situated with their sides at an angle of substantiallyforty-five degrees,-a steamdome extending along the apex of the outershell and having each side thereof secured to and forming in effect acontinuation of the adjacent side wall of said outer shell, and a staym'ember spanning a throat of the dome.

13. In a boiler, two concentric shells forming between them awater-chamber, each shell being substantially rectangular incross-section and situated with its sides at an angle of substantiallyforty-five degrees, a particylindrical steam-dome extendinglongitudinally of the boiler and having each side secured to the edge ofthe adjacent side wall of the outer shell.

14:. In a locomotive-boiler, two concentric shells forming between thema water-chamber, each shell being substantially square in cross-sectionand having its diagonals situated vertically and horizontallyrespectively, a steam-dome extending longitudinally of the boiler andconnected thereto throughout its length, each side of the dome beingsecured to the edge of the adjacent sidewall of the outer shell, and astay member spanning the throat of the dome.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES M. MOCLELLON.

